Game Theory and Predator–Prey Response Races

Abstract

Abstract A key issue in ecology is the study of animal habitat or patch use. Why are animals where they are? Why do they go where they go? In the past three decades, behavioral ecologists have focused on the effects of foraging, competition, and predation risk on habitat use. Optimality theory and its cousin, game theory, have provided conceptual frameworks guiding work in this field (Stephens&Krebs 1986, Mangel&Clark 1988, Milinski&Parker 1991; Brown, this volume). In the absence of predation risk, individual foragers often show patch use pat terns that are consistent with the goal of maximizing rates of net energy intake (Stephens&Krebs 1986; Brown, this volume). In the absence of competition, energy maximizing behaviors can be assessed without considering strategies shown by other foragers. Competition and predation risk, however, clearly influence patterns of patch use. Because the presence of competitors generally causes a reduction in individual feeding rates (Hassell 1978, Schoener 1983), the value of a given patch for an individual forager depends on the patch use of its competitors. When the value of each behavioral option (here, time spent foraging in each patch) depends on decisions made by other individuals, the appropriate conceptual framework is game theory (Maynard Smith 1982). Ideal free distribution (IFD) theory uses game theory to predict patch use patterns in a world with competition for resources (Fretwell 1972, Milinski&Parker 1991, Kacelnik et al. 1992).